This is ridiculous. When I throw parties I tell a couple of my friends and tell them to tell others and people just show up. Americans are living in some sort of parallel dimension.

There are certain kinds of styles of gatherings that do much better when there are 40-50 people present, rather than 10-20. If you are going for a low pressure hang and want 10-20, it's easy enough to just tell friends and tell them to tell others, you'll hit those numbers easy. If you are trying to do something a bit more memorable and you want to guarantee a higher turnout, you have to invest more effort into ensuring attendance. If you can get 50+ people to "just show up" without putting effort in, that means _someone_ (one of your friends) is putting the effort in, you're in college, or you're just super hot and famous

I am not American. Adults with obligations are harder to get into the same room. When you do it regularly, you have to get better at it.

Sometimes you also need to know who will be there because if half the group flakes out, the logistics fall apart. Not every party is a house party.

indeed. It's a flaky culture where half the people you do invite may not make it last minute. Let alone any friends they'd invite. Turns out hyperindividualism doesn't work well when you want to engage in social gatherings.